For kids (and not just kids) so used to cinema's special effects, computer games' hyperrealistic fantasy worlds and even theatres' incorporation of multimedia, the idea of one man on a bare stage without even any props for support may not be the most enticing. It's an idea that lasts about the 30 seconds it takes Julien Cottereau's everyman cleaner to notice us, as he polishes a window here, sweeps some papers away there and snacks on a banana.

From that moment, we're whisked into a world in which a monster sleeps at the back of the stage, dogs of different sizes are friendly and not so friendly, and piece of chewing gum becomes a double bass. All this exists, fully formed in our heads, as a result of M. Cottereau's suggestion of such through mime, sound and lighting. This conjuring of materials from the immaterial has an elemental, prehistoric quality to it, akin to seeing shapes in a fire as tales are told outside caves in the depths of winter.

The kids love it - transfixed and amazed as the clown unlocks parts of their minds they never knew they had. The adults love it too - but we might be working a little harder than the kids, keen to make sure that we don't miss the next crazy caper's layers of invention.

Not only is M. Cottereau technically gifted, a master of his art after years of study and practice all over the world with the likes of Cirque du Soleil, he also channels the timeless vulnerability and charisma of a Buster Keaton. That's how the audience participation scenes become a warm community experience, rather than an exploiting of the stooge's inability to mime like the master. It also adds a further chaotic element for the clown to twist and turn for invention and laughs.

Imagine Toi (at the Purcell Room, Southbank Centre until 24 December) is a fantastic opportunity to see a unique performer provoke laughter and wonder for an audience aged four to ninety-four - the perfect Christmas treat.